| // Copyright 2024 The Wuffs Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // https://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| // |
| // SPDX-License-Identifier: Apache-2.0 OR MIT |
| |
| // ---------------- |
| |
| // This is a small, self-contained, single-file C library to convert pixel data |
| // to the PNG file format, without using any compression. |
| // |
| // To use this file as a "foo.c"-like implementation, instead of a "foo.h"-like |
| // header, #define UNCOMPNG_IMPLEMENTATION before #include'ing or compiling it. |
| // |
| // As an option, you may also #define UNCOMPNG_CONFIG__STATIC_FUNCTIONS to make |
| // these functions have static storage. This can help the compiler ignore or |
| // discard unused code, which can produce faster compiles and smaller binaries. |
| // |
| // It is a C port of the github.com/google/wuffs/lib/uncompng library. The |
| // original Go code has much more comments about the algorithmic details. |
| |
| #ifndef UNCOMPNG_INCLUDE_GUARD |
| #define UNCOMPNG_INCLUDE_GUARD |
| |
| #if defined(UNCOMPNG_CONFIG__STATIC_FUNCTIONS) |
| #define UNCOMPNG__MAYBE_STATIC static |
| #else |
| #define UNCOMPNG__MAYBE_STATIC |
| #endif |
| |
| #include <stdbool.h> |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| // clang-format off |
| |
| // UNCOMPNG__PIXEL_FORMAT__ETC are the valid pixel_format values to pass to |
| // uncompng__encode. |
| // |
| // These constants' values are the same as the corresponding Wuffs definitions, |
| // after replacing the name's "WUFFS_BASE" prefix with "UNCOMPNG". This file is |
| // stand-alone. It does not #include any Wuffs code. |
| #define UNCOMPNG__PIXEL_FORMAT__Y 0x20000008 |
| #define UNCOMPNG__PIXEL_FORMAT__Y_16LE 0x2000000B |
| #define UNCOMPNG__PIXEL_FORMAT__YXXX 0x30008888 |
| #define UNCOMPNG__PIXEL_FORMAT__YXXX_4X16LE 0x3000BBBB |
| #define UNCOMPNG__PIXEL_FORMAT__BGRA_NONPREMUL 0x81008888 |
| #define UNCOMPNG__PIXEL_FORMAT__BGRA_NONPREMUL_4X16LE 0x8100BBBB |
| #define UNCOMPNG__PIXEL_FORMAT__BGRX 0x90008888 |
| #define UNCOMPNG__PIXEL_FORMAT__BGRX_4X16LE 0x9000BBBB |
| |
| // clang-format on |
| |
| // UNCOMPNG__RESULT__ETC can be returned by uncompng__encode. write_func can |
| // also return its own negative error codes, which are passed on. |
| #define UNCOMPNG__RESULT__OK 0 |
| #define UNCOMPNG__RESULT__INVALID_ARGUMENT 1 |
| #define UNCOMPNG__RESULT__UNSUPPORTED_IMAGE_SIZE 2 |
| #define UNCOMPNG__RESULT__CONCURRENT_CALL 3 |
| |
| // UNCOMPNG__DATA_LEN__INCL_MAX is the inclusive maximum value of write_func's |
| // data_len argument. In hexadecimal, it equals 0x10000u. |
| #define UNCOMPNG__DATA_LEN__INCL_MAX 65536u |
| |
| // uncompng__encode writes pixel data in PNG format to write_func. The callback |
| // may be run multiple times. Each time, write_func is expected to handle the |
| // entirety of the (data_ptr, data_len) slice. data_len will never exceed |
| // UNCOMPNG__DATA_LEN__INCL_MAX. |
| // |
| // write_func should return zero for success or non-zero for failure (which is |
| // passed back to the uncompng__encode caller). Returning a positive number is |
| // not recommended, as that may clash with UNCOMPNG__RESULT__ETC values. |
| // |
| // The context argument is unused other than being an opaque value that is |
| // forwarded on to write_func. |
| // |
| // Pixel data is in the (pixel_ptr, pixel_len) slice, either 1 or 4 bytes per |
| // pixel depending on the pixel_format. width and height are measured in |
| // pixels. stride, the pointer difference between rows, is measured in bytes. |
| // |
| // This function is not thread-safe. |
| UNCOMPNG__MAYBE_STATIC int // |
| uncompng__encode(int (*write_func)(void* context, |
| const uint8_t* data_ptr, |
| size_t data_len), |
| void* context, |
| const uint8_t* pixel_ptr, |
| size_t pixel_len, |
| uint32_t width, |
| uint32_t height, |
| size_t stride, |
| uint32_t pixel_format); |
| |
| // -------- |
| |
| #ifdef UNCOMPNG_IMPLEMENTATION |
| |
| static uint32_t // |
| uncompng__private_impl_crc32_ieee(const uint8_t* ptr, size_t len) { |
| static const uint32_t table[256] = { |
| 0x00000000u, 0x77073096u, 0xEE0E612Cu, 0x990951BAu, 0x076DC419u, |
| 0x706AF48Fu, 0xE963A535u, 0x9E6495A3u, 0x0EDB8832u, 0x79DCB8A4u, |
| 0xE0D5E91Eu, 0x97D2D988u, 0x09B64C2Bu, 0x7EB17CBDu, 0xE7B82D07u, |
| 0x90BF1D91u, 0x1DB71064u, 0x6AB020F2u, 0xF3B97148u, 0x84BE41DEu, |
| 0x1ADAD47Du, 0x6DDDE4EBu, 0xF4D4B551u, 0x83D385C7u, 0x136C9856u, |
| 0x646BA8C0u, 0xFD62F97Au, 0x8A65C9ECu, 0x14015C4Fu, 0x63066CD9u, |
| 0xFA0F3D63u, 0x8D080DF5u, 0x3B6E20C8u, 0x4C69105Eu, 0xD56041E4u, |
| 0xA2677172u, 0x3C03E4D1u, 0x4B04D447u, 0xD20D85FDu, 0xA50AB56Bu, |
| 0x35B5A8FAu, 0x42B2986Cu, 0xDBBBC9D6u, 0xACBCF940u, 0x32D86CE3u, |
| 0x45DF5C75u, 0xDCD60DCFu, 0xABD13D59u, 0x26D930ACu, 0x51DE003Au, |
| 0xC8D75180u, 0xBFD06116u, 0x21B4F4B5u, 0x56B3C423u, 0xCFBA9599u, |
| 0xB8BDA50Fu, 0x2802B89Eu, 0x5F058808u, 0xC60CD9B2u, 0xB10BE924u, |
| 0x2F6F7C87u, 0x58684C11u, 0xC1611DABu, 0xB6662D3Du, 0x76DC4190u, |
| 0x01DB7106u, 0x98D220BCu, 0xEFD5102Au, 0x71B18589u, 0x06B6B51Fu, |
| 0x9FBFE4A5u, 0xE8B8D433u, 0x7807C9A2u, 0x0F00F934u, 0x9609A88Eu, |
| 0xE10E9818u, 0x7F6A0DBBu, 0x086D3D2Du, 0x91646C97u, 0xE6635C01u, |
| 0x6B6B51F4u, 0x1C6C6162u, 0x856530D8u, 0xF262004Eu, 0x6C0695EDu, |
| 0x1B01A57Bu, 0x8208F4C1u, 0xF50FC457u, 0x65B0D9C6u, 0x12B7E950u, |
| 0x8BBEB8EAu, 0xFCB9887Cu, 0x62DD1DDFu, 0x15DA2D49u, 0x8CD37CF3u, |
| 0xFBD44C65u, 0x4DB26158u, 0x3AB551CEu, 0xA3BC0074u, 0xD4BB30E2u, |
| 0x4ADFA541u, 0x3DD895D7u, 0xA4D1C46Du, 0xD3D6F4FBu, 0x4369E96Au, |
| 0x346ED9FCu, 0xAD678846u, 0xDA60B8D0u, 0x44042D73u, 0x33031DE5u, |
| 0xAA0A4C5Fu, 0xDD0D7CC9u, 0x5005713Cu, 0x270241AAu, 0xBE0B1010u, |
| 0xC90C2086u, 0x5768B525u, 0x206F85B3u, 0xB966D409u, 0xCE61E49Fu, |
| 0x5EDEF90Eu, 0x29D9C998u, 0xB0D09822u, 0xC7D7A8B4u, 0x59B33D17u, |
| 0x2EB40D81u, 0xB7BD5C3Bu, 0xC0BA6CADu, 0xEDB88320u, 0x9ABFB3B6u, |
| 0x03B6E20Cu, 0x74B1D29Au, 0xEAD54739u, 0x9DD277AFu, 0x04DB2615u, |
| 0x73DC1683u, 0xE3630B12u, 0x94643B84u, 0x0D6D6A3Eu, 0x7A6A5AA8u, |
| 0xE40ECF0Bu, 0x9309FF9Du, 0x0A00AE27u, 0x7D079EB1u, 0xF00F9344u, |
| 0x8708A3D2u, 0x1E01F268u, 0x6906C2FEu, 0xF762575Du, 0x806567CBu, |
| 0x196C3671u, 0x6E6B06E7u, 0xFED41B76u, 0x89D32BE0u, 0x10DA7A5Au, |
| 0x67DD4ACCu, 0xF9B9DF6Fu, 0x8EBEEFF9u, 0x17B7BE43u, 0x60B08ED5u, |
| 0xD6D6A3E8u, 0xA1D1937Eu, 0x38D8C2C4u, 0x4FDFF252u, 0xD1BB67F1u, |
| 0xA6BC5767u, 0x3FB506DDu, 0x48B2364Bu, 0xD80D2BDAu, 0xAF0A1B4Cu, |
| 0x36034AF6u, 0x41047A60u, 0xDF60EFC3u, 0xA867DF55u, 0x316E8EEFu, |
| 0x4669BE79u, 0xCB61B38Cu, 0xBC66831Au, 0x256FD2A0u, 0x5268E236u, |
| 0xCC0C7795u, 0xBB0B4703u, 0x220216B9u, 0x5505262Fu, 0xC5BA3BBEu, |
| 0xB2BD0B28u, 0x2BB45A92u, 0x5CB36A04u, 0xC2D7FFA7u, 0xB5D0CF31u, |
| 0x2CD99E8Bu, 0x5BDEAE1Du, 0x9B64C2B0u, 0xEC63F226u, 0x756AA39Cu, |
| 0x026D930Au, 0x9C0906A9u, 0xEB0E363Fu, 0x72076785u, 0x05005713u, |
| 0x95BF4A82u, 0xE2B87A14u, 0x7BB12BAEu, 0x0CB61B38u, 0x92D28E9Bu, |
| 0xE5D5BE0Du, 0x7CDCEFB7u, 0x0BDBDF21u, 0x86D3D2D4u, 0xF1D4E242u, |
| 0x68DDB3F8u, 0x1FDA836Eu, 0x81BE16CDu, 0xF6B9265Bu, 0x6FB077E1u, |
| 0x18B74777u, 0x88085AE6u, 0xFF0F6A70u, 0x66063BCAu, 0x11010B5Cu, |
| 0x8F659EFFu, 0xF862AE69u, 0x616BFFD3u, 0x166CCF45u, 0xA00AE278u, |
| 0xD70DD2EEu, 0x4E048354u, 0x3903B3C2u, 0xA7672661u, 0xD06016F7u, |
| 0x4969474Du, 0x3E6E77DBu, 0xAED16A4Au, 0xD9D65ADCu, 0x40DF0B66u, |
| 0x37D83BF0u, 0xA9BCAE53u, 0xDEBB9EC5u, 0x47B2CF7Fu, 0x30B5FFE9u, |
| 0xBDBDF21Cu, 0xCABAC28Au, 0x53B39330u, 0x24B4A3A6u, 0xBAD03605u, |
| 0xCDD70693u, 0x54DE5729u, 0x23D967BFu, 0xB3667A2Eu, 0xC4614AB8u, |
| 0x5D681B02u, 0x2A6F2B94u, 0xB40BBE37u, 0xC30C8EA1u, 0x5A05DF1Bu, |
| 0x2D02EF8Du, |
| }; |
| |
| uint32_t hash = 0xFFFFFFFFu; |
| while (len--) { |
| hash = table[(uint8_t)hash ^ (*ptr++)] ^ (hash >> 8); |
| } |
| return hash ^ 0xFFFFFFFFu; |
| } |
| |
| static uint8_t uncompng__private_impl_buffer[65536]; |
| |
| static void // |
| uncompng__private_impl_initialize_buffer(uint32_t width, |
| uint32_t height, |
| uint32_t pixel_format) { |
| uncompng__private_impl_buffer[0x0000] = 0x89; |
| uncompng__private_impl_buffer[0x0001] = 'P'; |
| uncompng__private_impl_buffer[0x0002] = 'N'; |
| uncompng__private_impl_buffer[0x0003] = 'G'; |
| uncompng__private_impl_buffer[0x0004] = 0x0D; |
| uncompng__private_impl_buffer[0x0005] = 0x0A; |
| uncompng__private_impl_buffer[0x0006] = 0x1A; |
| uncompng__private_impl_buffer[0x0007] = 0x0A; |
| uncompng__private_impl_buffer[0x0008] = 0; |
| uncompng__private_impl_buffer[0x0009] = 0; |
| uncompng__private_impl_buffer[0x000A] = 0; |
| uncompng__private_impl_buffer[0x000B] = 0x0D; |
| uncompng__private_impl_buffer[0x000C] = 'I'; |
| uncompng__private_impl_buffer[0x000D] = 'H'; |
| uncompng__private_impl_buffer[0x000E] = 'D'; |
| uncompng__private_impl_buffer[0x000F] = 'R'; |
| uncompng__private_impl_buffer[0x0010] = (uint8_t)(width >> 24); |
| uncompng__private_impl_buffer[0x0011] = (uint8_t)(width >> 16); |
| uncompng__private_impl_buffer[0x0012] = (uint8_t)(width >> 8); |
| uncompng__private_impl_buffer[0x0013] = (uint8_t)(width >> 0); |
| uncompng__private_impl_buffer[0x0014] = (uint8_t)(height >> 24); |
| uncompng__private_impl_buffer[0x0015] = (uint8_t)(height >> 16); |
| uncompng__private_impl_buffer[0x0016] = (uint8_t)(height >> 8); |
| uncompng__private_impl_buffer[0x0017] = (uint8_t)(height >> 0); |
| |
| uint8_t depth; |
| uint8_t color_type; |
| switch (pixel_format) { |
| case UNCOMPNG__PIXEL_FORMAT__Y: |
| case UNCOMPNG__PIXEL_FORMAT__YXXX: |
| depth = 8; |
| color_type = 0; |
| break; |
| case UNCOMPNG__PIXEL_FORMAT__BGRA_NONPREMUL: |
| depth = 8; |
| color_type = 6; |
| break; |
| case UNCOMPNG__PIXEL_FORMAT__BGRX: |
| depth = 8; |
| color_type = 2; |
| break; |
| case UNCOMPNG__PIXEL_FORMAT__Y_16LE: |
| case UNCOMPNG__PIXEL_FORMAT__YXXX_4X16LE: |
| depth = 16; |
| color_type = 0; |
| break; |
| case UNCOMPNG__PIXEL_FORMAT__BGRA_NONPREMUL_4X16LE: |
| depth = 16; |
| color_type = 6; |
| break; |
| case UNCOMPNG__PIXEL_FORMAT__BGRX_4X16LE: |
| depth = 16; |
| color_type = 2; |
| break; |
| default: |
| return; |
| } |
| uncompng__private_impl_buffer[0x0018] = depth; |
| uncompng__private_impl_buffer[0x0019] = color_type; |
| uncompng__private_impl_buffer[0x001A] = 0; |
| uncompng__private_impl_buffer[0x001B] = 0; |
| uncompng__private_impl_buffer[0x001C] = 0; |
| |
| uint32_t ihdr_crc32 = uncompng__private_impl_crc32_ieee( |
| uncompng__private_impl_buffer + 0x000C, 0x001D - 0x000C); |
| uncompng__private_impl_buffer[0x001D] = (uint8_t)(ihdr_crc32 >> 24); |
| uncompng__private_impl_buffer[0x001E] = (uint8_t)(ihdr_crc32 >> 16); |
| uncompng__private_impl_buffer[0x001F] = (uint8_t)(ihdr_crc32 >> 8); |
| uncompng__private_impl_buffer[0x0020] = (uint8_t)(ihdr_crc32 >> 0); |
| |
| uncompng__private_impl_buffer[0x0021] = 0; |
| uncompng__private_impl_buffer[0x0022] = 0; |
| uncompng__private_impl_buffer[0x0023] = 0; |
| uncompng__private_impl_buffer[0x0024] = 0; |
| uncompng__private_impl_buffer[0x0025] = 'I'; |
| uncompng__private_impl_buffer[0x0026] = 'D'; |
| uncompng__private_impl_buffer[0x0027] = 'A'; |
| uncompng__private_impl_buffer[0x0028] = 'T'; |
| uncompng__private_impl_buffer[0x0029] = 0x78; |
| uncompng__private_impl_buffer[0x002A] = 0x01; |
| uncompng__private_impl_buffer[0x002B] = 0; |
| uncompng__private_impl_buffer[0x002C] = 0; |
| uncompng__private_impl_buffer[0x002D] = 0; |
| uncompng__private_impl_buffer[0x002E] = 0; |
| uncompng__private_impl_buffer[0x002F] = 0; |
| uncompng__private_impl_buffer[0xFFFC] = 0; |
| uncompng__private_impl_buffer[0xFFFD] = 0; |
| uncompng__private_impl_buffer[0xFFFE] = 0; |
| uncompng__private_impl_buffer[0xFFFF] = 1; |
| } |
| |
| static void // |
| uncompng__private_impl_update_adler32(int ei, int ej) { |
| uint32_t b = ((uint32_t)uncompng__private_impl_buffer[0xFFFC] << 8) | |
| ((uint32_t)uncompng__private_impl_buffer[0xFFFD]); |
| uint32_t a = ((uint32_t)uncompng__private_impl_buffer[0xFFFE] << 8) | |
| ((uint32_t)uncompng__private_impl_buffer[0xFFFF]); |
| while (ei < ej) { |
| int end = ei + 5552; |
| if (end > ej) { |
| end = ej; |
| } |
| for (; ei < end; ei++) { |
| a += (uint32_t)uncompng__private_impl_buffer[ei]; |
| b += a; |
| } |
| a %= 65521; |
| b %= 65521; |
| } |
| uncompng__private_impl_buffer[0xFFFC] = (uint8_t)(b >> 8); |
| uncompng__private_impl_buffer[0xFFFD] = (uint8_t)(b >> 0); |
| uncompng__private_impl_buffer[0xFFFE] = (uint8_t)(a >> 8); |
| uncompng__private_impl_buffer[0xFFFF] = (uint8_t)(a >> 0); |
| } |
| |
| static int // |
| uncompng__private_impl_flush(int (*write_func)(void* context, |
| const uint8_t* data_ptr, |
| size_t data_len), |
| void* context, |
| int ej, |
| bool final) { |
| static const int ei_first = 0x0030; |
| static const int ei_later = 0x000D; |
| |
| int crc32_start = 0; |
| int ei = 0; |
| if (uncompng__private_impl_buffer[0x0004] == 0x0D) { |
| uint32_t idat_chunk_len = ej - 0x0029; |
| if (final) { |
| idat_chunk_len += 4; |
| } |
| uncompng__private_impl_buffer[0x0021] = (uint8_t)(idat_chunk_len >> 24); |
| uncompng__private_impl_buffer[0x0022] = (uint8_t)(idat_chunk_len >> 16); |
| uncompng__private_impl_buffer[0x0023] = (uint8_t)(idat_chunk_len >> 8); |
| uncompng__private_impl_buffer[0x0024] = (uint8_t)(idat_chunk_len >> 0); |
| crc32_start = 0x0025; |
| ei = ei_first; |
| } else { |
| uint32_t idat_chunk_len = ej - 0x0008; |
| if (final) { |
| idat_chunk_len += 4; |
| } |
| uncompng__private_impl_buffer[0x0000] = (uint8_t)(idat_chunk_len >> 24); |
| uncompng__private_impl_buffer[0x0001] = (uint8_t)(idat_chunk_len >> 16); |
| uncompng__private_impl_buffer[0x0002] = (uint8_t)(idat_chunk_len >> 8); |
| uncompng__private_impl_buffer[0x0003] = (uint8_t)(idat_chunk_len >> 0); |
| crc32_start = 0x0004; |
| ei = ei_later; |
| } |
| |
| uint32_t deflate_block_len = (uint32_t)(ej - ei); |
| uncompng__private_impl_buffer[ei - 5] = final ? 1 : 0; |
| uncompng__private_impl_buffer[ei - 4] = |
| 0x00u ^ (uint8_t)(deflate_block_len >> 0); |
| uncompng__private_impl_buffer[ei - 3] = |
| 0x00u ^ (uint8_t)(deflate_block_len >> 8); |
| uncompng__private_impl_buffer[ei - 2] = |
| 0xFFu ^ (uint8_t)(deflate_block_len >> 0); |
| uncompng__private_impl_buffer[ei - 1] = |
| 0xFFu ^ (uint8_t)(deflate_block_len >> 8); |
| |
| uncompng__private_impl_update_adler32(ei, ej); |
| if (final) { |
| uncompng__private_impl_buffer[ej + 0] = |
| uncompng__private_impl_buffer[0xFFFC]; |
| uncompng__private_impl_buffer[ej + 1] = |
| uncompng__private_impl_buffer[0xFFFD]; |
| uncompng__private_impl_buffer[ej + 2] = |
| uncompng__private_impl_buffer[0xFFFE]; |
| uncompng__private_impl_buffer[ej + 3] = |
| uncompng__private_impl_buffer[0xFFFF]; |
| ej += 4; |
| } |
| |
| uint32_t idat_crc32 = uncompng__private_impl_crc32_ieee( |
| uncompng__private_impl_buffer + crc32_start, ej - crc32_start); |
| uncompng__private_impl_buffer[ej + 0] = (uint8_t)(idat_crc32 >> 24); |
| uncompng__private_impl_buffer[ej + 1] = (uint8_t)(idat_crc32 >> 16); |
| uncompng__private_impl_buffer[ej + 2] = (uint8_t)(idat_crc32 >> 8); |
| uncompng__private_impl_buffer[ej + 3] = (uint8_t)(idat_crc32 >> 0); |
| ej += 4; |
| |
| if (!final) { |
| int err0 = |
| (*write_func)(context, uncompng__private_impl_buffer, (size_t)ej); |
| if (err0 != 0) { |
| return err0; |
| } |
| uncompng__private_impl_buffer[0x0004] = 'I'; |
| uncompng__private_impl_buffer[0x0005] = 'D'; |
| uncompng__private_impl_buffer[0x0006] = 'A'; |
| uncompng__private_impl_buffer[0x0007] = 'T'; |
| return 0; |
| } |
| |
| static const uint8_t iend_chunk[] = { |
| 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82, |
| }; |
| |
| bool write_separate_iend_chunk = (ej + 12) > 65536; |
| if (!write_separate_iend_chunk) { |
| for (int i = 0; i < 12; i++) { |
| uncompng__private_impl_buffer[ej++] = iend_chunk[i]; |
| } |
| } |
| |
| int err1 = (*write_func)(context, uncompng__private_impl_buffer, (size_t)ej); |
| if (err1 != 0) { |
| return err1; |
| } |
| |
| if (write_separate_iend_chunk) { |
| int err2 = (*write_func)(context, iend_chunk, 12u); |
| if (err2 != 0) { |
| return err2; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int // |
| uncompng__private_impl_do_encode(int (*write_func)(void* context, |
| const uint8_t* data_ptr, |
| size_t data_len), |
| void* context, |
| const uint8_t* pixel_ptr, |
| size_t pixel_len, |
| uint32_t width, |
| uint32_t height, |
| size_t stride, |
| uint32_t pixel_format) { |
| static const int ei_first = 0x0030; |
| static const int ei_later = 0x000D; |
| static const int ej_max = 0xFFF8; |
| |
| uncompng__private_impl_initialize_buffer(width, height, pixel_format); |
| |
| int ej = ei_first; |
| |
| for (uint32_t y = 0; y < height; y++) { |
| if ((ej + 1) > ej_max) { |
| int err = uncompng__private_impl_flush(write_func, context, ej, false); |
| if (err != 0) { |
| return err; |
| } |
| ej = ei_later; |
| } |
| uncompng__private_impl_buffer[ej++] = 0; |
| |
| const uint8_t* row = pixel_ptr + (stride * y); |
| |
| switch (pixel_format) { |
| case UNCOMPNG__PIXEL_FORMAT__Y: |
| for (uint32_t x = 0; x < width; x++) { |
| if ((ej + 1) > ej_max) { |
| int err = |
| uncompng__private_impl_flush(write_func, context, ej, false); |
| if (err != 0) { |
| return err; |
| } |
| ej = ei_later; |
| } |
| uncompng__private_impl_buffer[ej++] = row[0]; |
| row += 1; |
| } |
| break; |
| |
| case UNCOMPNG__PIXEL_FORMAT__Y_16LE: |
| for (uint32_t x = 0; x < width; x++) { |
| if ((ej + 2) > ej_max) { |
| int err = |
| uncompng__private_impl_flush(write_func, context, ej, false); |
| if (err != 0) { |
| return err; |
| } |
| ej = ei_later; |
| } |
| uncompng__private_impl_buffer[ej++] = row[1]; |
| uncompng__private_impl_buffer[ej++] = row[0]; |
| row += 2; |
| } |
| break; |
| |
| case UNCOMPNG__PIXEL_FORMAT__YXXX: |
| for (uint32_t x = 0; x < width; x++) { |
| if ((ej + 1) > ej_max) { |
| int err = |
| uncompng__private_impl_flush(write_func, context, ej, false); |
| if (err != 0) { |
| return err; |
| } |
| ej = ei_later; |
| } |
| uncompng__private_impl_buffer[ej++] = row[0]; |
| row += 4; |
| } |
| break; |
| |
| case UNCOMPNG__PIXEL_FORMAT__YXXX_4X16LE: |
| for (uint32_t x = 0; x < width; x++) { |
| if ((ej + 2) > ej_max) { |
| int err = |
| uncompng__private_impl_flush(write_func, context, ej, false); |
| if (err != 0) { |
| return err; |
| } |
| ej = ei_later; |
| } |
| uncompng__private_impl_buffer[ej++] = row[1]; |
| uncompng__private_impl_buffer[ej++] = row[0]; |
| row += 8; |
| } |
| break; |
| |
| case UNCOMPNG__PIXEL_FORMAT__BGRA_NONPREMUL: |
| for (uint32_t x = 0; x < width; x++) { |
| if ((ej + 4) > ej_max) { |
| int err = |
| uncompng__private_impl_flush(write_func, context, ej, false); |
| if (err != 0) { |
| return err; |
| } |
| ej = ei_later; |
| } |
| uncompng__private_impl_buffer[ej++] = row[2]; |
| uncompng__private_impl_buffer[ej++] = row[1]; |
| uncompng__private_impl_buffer[ej++] = row[0]; |
| uncompng__private_impl_buffer[ej++] = row[3]; |
| row += 4; |
| } |
| break; |
| |
| case UNCOMPNG__PIXEL_FORMAT__BGRA_NONPREMUL_4X16LE: |
| for (uint32_t x = 0; x < width; x++) { |
| if ((ej + 8) > ej_max) { |
| int err = |
| uncompng__private_impl_flush(write_func, context, ej, false); |
| if (err != 0) { |
| return err; |
| } |
| ej = ei_later; |
| } |
| uncompng__private_impl_buffer[ej++] = row[5]; |
| uncompng__private_impl_buffer[ej++] = row[4]; |
| uncompng__private_impl_buffer[ej++] = row[3]; |
| uncompng__private_impl_buffer[ej++] = row[2]; |
| uncompng__private_impl_buffer[ej++] = row[1]; |
| uncompng__private_impl_buffer[ej++] = row[0]; |
| uncompng__private_impl_buffer[ej++] = row[7]; |
| uncompng__private_impl_buffer[ej++] = row[6]; |
| row += 8; |
| } |
| break; |
| |
| case UNCOMPNG__PIXEL_FORMAT__BGRX: |
| for (uint32_t x = 0; x < width; x++) { |
| if ((ej + 3) > ej_max) { |
| int err = |
| uncompng__private_impl_flush(write_func, context, ej, false); |
| if (err != 0) { |
| return err; |
| } |
| ej = ei_later; |
| } |
| uncompng__private_impl_buffer[ej++] = row[2]; |
| uncompng__private_impl_buffer[ej++] = row[1]; |
| uncompng__private_impl_buffer[ej++] = row[0]; |
| row += 4; |
| } |
| break; |
| |
| case UNCOMPNG__PIXEL_FORMAT__BGRX_4X16LE: |
| for (uint32_t x = 0; x < width; x++) { |
| if ((ej + 6) > ej_max) { |
| int err = |
| uncompng__private_impl_flush(write_func, context, ej, false); |
| if (err != 0) { |
| return err; |
| } |
| ej = ei_later; |
| } |
| uncompng__private_impl_buffer[ej++] = row[5]; |
| uncompng__private_impl_buffer[ej++] = row[4]; |
| uncompng__private_impl_buffer[ej++] = row[3]; |
| uncompng__private_impl_buffer[ej++] = row[2]; |
| uncompng__private_impl_buffer[ej++] = row[1]; |
| uncompng__private_impl_buffer[ej++] = row[0]; |
| row += 8; |
| } |
| break; |
| |
| default: |
| return UNCOMPNG__RESULT__INVALID_ARGUMENT; |
| } |
| } |
| |
| return uncompng__private_impl_flush(write_func, context, ej, true); |
| } |
| |
| UNCOMPNG__MAYBE_STATIC int // |
| uncompng__encode(int (*write_func)(void* context, |
| const uint8_t* data_ptr, |
| size_t data_len), |
| void* context, |
| const uint8_t* pixel_ptr, |
| size_t pixel_len, |
| uint32_t width, |
| uint32_t height, |
| size_t stride, |
| uint32_t pixel_format) { |
| if (!write_func) { |
| return UNCOMPNG__RESULT__INVALID_ARGUMENT; |
| } |
| uint64_t bytes_per_pixel; |
| switch (pixel_format) { |
| case UNCOMPNG__PIXEL_FORMAT__Y: |
| bytes_per_pixel = 1u; |
| break; |
| case UNCOMPNG__PIXEL_FORMAT__Y_16LE: |
| bytes_per_pixel = 2u; |
| break; |
| case UNCOMPNG__PIXEL_FORMAT__YXXX: |
| case UNCOMPNG__PIXEL_FORMAT__BGRA_NONPREMUL: |
| case UNCOMPNG__PIXEL_FORMAT__BGRX: |
| bytes_per_pixel = 4u; |
| break; |
| case UNCOMPNG__PIXEL_FORMAT__YXXX_4X16LE: |
| case UNCOMPNG__PIXEL_FORMAT__BGRA_NONPREMUL_4X16LE: |
| case UNCOMPNG__PIXEL_FORMAT__BGRX_4X16LE: |
| bytes_per_pixel = 8u; |
| break; |
| default: |
| return UNCOMPNG__RESULT__INVALID_ARGUMENT; |
| } |
| if ((width > 0xFFFFFFu) || (height > 0xFFFFFFu) || (stride >= 0xFFFFFFFFu)) { |
| return UNCOMPNG__RESULT__UNSUPPORTED_IMAGE_SIZE; |
| } |
| |
| if (height > 0u) { |
| // This calculation is similar to the one used in |
| // wuffs_base__table__flattened_length. |
| uint64_t n = ((uint64_t)stride * (uint64_t)(height - 1u)) + |
| (bytes_per_pixel * (uint64_t)width); |
| if (pixel_len < n) { |
| return UNCOMPNG__RESULT__INVALID_ARGUMENT; |
| } |
| } |
| |
| // uncompng__private_impl_buffer is a global variable in this C code, unlike |
| // the original Go code, so try to reject concurrent use. This isn't perfect, |
| // as it doesn't use atomics, but it's better than nothing. |
| static volatile bool concurrent = false; |
| if (concurrent) { |
| return UNCOMPNG__RESULT__CONCURRENT_CALL; |
| } |
| concurrent = true; |
| int ret = uncompng__private_impl_do_encode(write_func, context, pixel_ptr, |
| pixel_len, width, height, stride, |
| pixel_format); |
| concurrent = false; |
| return ret; |
| } |
| |
| #endif // UNCOMPNG_IMPLEMENTATION |
| #endif // UNCOMPNG_INCLUDE_GUARD |
